1. Field of the Invention
The present invention relates to a process for producing a hydrocarbon resin having a high softening point of from 130.degree. to 140.degree. C. and excellent solubility in a hydrocarbon solvent containing no aromatic component useful for printing ink or the like.
2. Discussion of Background
Aromatic hydrocarbons such as toluene and xylene have been commonly employed as solvents for printing ink for such reasons that they are inexpensive and provide excellent solubility, and they have narrow boiling point ranges so that the evaporation can readily be adjusted.
However, aromatic hydrocarbon solvents are per se harmful to human bodies and can be dangerous when they are dissipated in the atomsphere. Therefore, in recent years, there have been various restrictions or controls against their discharge or against their use. As a measure to cope with this problem, turning to relatively safe non-aromatic solvents has been desired, and this trend is also true for solvents for coating materials.
Aliphatic hydrocarbon resins and terpene resins having good solubility in non-aromatic solvents are hardly obtainable as resins having a high softening point of at least 130.degree. C.
Conventional aromatic hydrocarbon resins having a softening point of at least 130.degree. C. are inferior in the solubility because of their polarity. For example, the resins proposed in Japanese Examined Patent Publication No. 32432/1973 are not necessarily adequate in the solubility since they use phenols.